Managing an optical network involves both network commissioning and upgrading. Commissioning an optical network is an important step in making the network ready for use after its installation is complete. Network commissioning concerns the deployment of network nodes for making them operational and includes the adjustment of various operational parameters in the node and testing to ascertain that the deployed network meets its specifications. Moreover, the capability to upgrade an existing network, through addition and deletion of nodes as well as through making changes in the configuration of an existing node are often necessary after the network has been commissioned. A node in an optical network contains a number of components such as amplifiers, blockers and attenuators. Fixing the operational parameters for the different components such as amplifier gains that are estimated during the link planning stage is a major objective for network commissioning and upgrading. Using an optical signal source at various nodes in the network and making measurements at the output of various components are required to achieve this objective. A removable laser source is typically used in prior art for this purpose. The laser source is attached to a particular node and the resulting signals are then measured at various points in the network. For completing the network installation, however, the laser source needs to be attached to various nodes in the network. One of the major problems with this approach is that the laser source is to be moved manually from one node to another leading to long network commissioning times. Another problem is that, additional hardware is needed, giving rise to extra costs, and additional logistics problems. Thus there is a need in the field for the development of an improved and efficient method for commissioning and upgrading of an optical network.